On unique stone beaches on the Arctic coast of the Kola Peninsula

Abstract

The results of studies of 11 stone beaches on the coast of the Barents Sea in the area of the Teriberskaya Bay have been presented. The studies were carried out from 2017 to 2019. As a result of the work, the structure of the beaches, their size, the composition of clastic material and the relationship with bedrocks were studied in detail. The genetic link between beaches and sea terraces has been established. Special attention has been paid to the morphology of beach clastic material, the conditions of its formation, and its role in abrasion activity. It has been shown that the clastic material of the beaches mainly corresponds to boulders equal to 100–1,000 mm, to a lesser extent to pebbles 10–100 mm, and rarely – gravel 1–10 mm. Individual boulders reach 2,000 mm. Sandy fractions in the composition of beach sediments are practically absent. The roundness of the fragments is high, semi-circular and rounded grains predominate, the most perfect shape of the rounded fragments is a biaxial ellipsoid or egg. Perfectly rounded boulders and pebbles in some areas account for up to 30 % of beach deposits. Measurements of the parameters of the egg-shaped pebbles have shown that they are close to the parameters of the "golden section" of the egg, i. e. meet the most durable form, resistant to destruction. Thus, the process of abrasion of the beach debris is directed towards their acquisition of the most energetically stable state. This suggests that the original shape of the debris contained a solid core in the form of a biaxial ellipsoid.

Keywords

• barents sea coast
• stone beach
• abrasion
• stone eggs
• побережье баренцева моря
• каменный пляж
• абразия
• каменные яйца